/**
 * Copyright      2020  Xiaomi Corporation (authors: Fangjun Kuang)
 *
 * See LICENSE for clarification regarding multiple authors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include "gtest/gtest.h"
#include "k2/csrc/algorithms.h"
#include "k2/csrc/math.h"

namespace k2 {
TEST(Math, HighestBitSet) {
  K2_CHECK_EQ(HighestBitSet(int32_t(0)), -1);
  K2_CHECK_EQ(HighestBitSet(int32_t(1)), 0);
  K2_CHECK_EQ(HighestBitSet(int32_t(2)), 1);
  K2_CHECK_EQ(HighestBitSet(int32_t(3)), 1);
  K2_CHECK_EQ(HighestBitSet(int32_t(4)), 2);
  K2_CHECK_EQ(HighestBitSet(int32_t(5)), 2);

  K2_CHECK_EQ(HighestBitSet(int32_t(1) << 29), 29);
  K2_CHECK_EQ(HighestBitSet((int32_t(1) << 29) + 1), 29);
  K2_CHECK_EQ(HighestBitSet(int32_t(1) << 30), 30);
  K2_CHECK_EQ(HighestBitSet((int32_t(1) << 30) + 1), 30);

  K2_CHECK_EQ(HighestBitSet(int64_t(0)), -1);
  K2_CHECK_EQ(HighestBitSet(int64_t(1)), 0);
  K2_CHECK_EQ(HighestBitSet(int64_t(2)), 1);
  K2_CHECK_EQ(HighestBitSet(int64_t(3)), 1);
  K2_CHECK_EQ(HighestBitSet(int64_t(4)), 2);
  K2_CHECK_EQ(HighestBitSet(int64_t(5)), 2);

  K2_CHECK_EQ(HighestBitSet(int64_t(1) << 50), 50);
  K2_CHECK_EQ(HighestBitSet((int64_t(1) << 50) + 1), 50);
}
}  // namespace k2
